1. Field of the Invention
Example embodiments generally relate to a switch actuation device, an interlock mechanism, and an image forming apparatus including the switch actuation device, for example, for actuating a switch.
2. Description of the Related Art
A related-art image forming apparatus, such as a copier, a printer, a facsimile machine, or a multifunction printer having at least one of copying, printing, scanning, and facsimile functions, typically forms an image on a sheet. To remove a jammed sheet or to replace consumables, such as a toner container, a cover of the image forming apparatus may be opened and closed. As a safety feature, an interlock mechanism included in the image forming apparatus may be turned on and off in correspondence with closing and opening of the cover so as to turn on and off a power source of the image forming apparatus. For example, when the cover is opened, the interlock mechanism is turned off to turn off the power source. Such interlock mechanism includes a switch connected to the power source.
Generally, the image forming apparatus includes a plurality of covers. If a plurality of interlock mechanisms is provided to correspond to the plurality of covers, a number of interlock mechanisms is increased, occupying a larger space and increasing manufacturing costs.
To address such problem, one example of the image forming apparatus includes a right lever provided on a right cover, a left lever provided on a left cover, and an actuation member provided on a front cover. The right lever and the left lever overlap each other at an overlap position at which a switch actuator is provided. When the front cover is closed and the actuation member provided on the front cover presses the overlapped right and left levers at the overlap position, the switch actuator turns on an interlock switch.
Another example of the image forming apparatus includes two front covers. When one of the two front covers is closed according to a predetermined order, a protrusion provided on the closed front cover presses a pair of engaged levers so as to disengage the levers. When another one of the two front covers is closed, one of the levers rotates to turn on an interlock switch.
However, in the above-described image forming apparatuses, when the plurality of covers is not closed in the predetermined order, the interlock switch may not be turned on.
To address this problem, yet another example of the image forming apparatus includes a front cover, a side cover, and a top cover. When one of the front cover and the side cover is closed, a link member swings to turn on an interlock switch. Even when the front cover and the side cover are not closed in a predetermined order, the top cover may swing the link member to turn on the interlock switch. However, an extra cover, that is, the top cover, is needed to turn on the interlock switch, resulting in a larger size of the image forming apparatus.
Yet another example of the image forming apparatus includes a plurality of swing members to turn on an interlock switch even when covers are not closed in a predetermined order. When the covers contact pivoting ends of the swing members, respectively, the swing members turn on the interlock switch. The covers need to have contact areas corresponding to swing strokes of the swing members, respectively. Therefore, when the covers and the swing members are not manufactured precisely or when an amount of opening and closing of the covers varies, the swing members may not swing properly, resulting in unstable or unreliable actuation of the interlock switch.
Moreover, in the image forming apparatuses in which the interlock switch may be turned on even when the plurality of covers is not closed in the predetermined order, a user of the image forming apparatus may not easily identify which cover is opened when the image forming apparatus is accidentally powered off.
Obviously, such increased size of the image forming apparatus and unreliable actuation of the interlock switch are undesirable, and accordingly, there is a need for a technology to provide stable actuation of the interlock switch with a compact structure and easy identification of an accidentally opened cover.